&#34;Reclosable Pouring Element for Composite Cardboard/Plastic Packaging&#34;

ABSTRACT

A reclosable pouring element for cardboard/plastic composite packagings, in particular beverage packagings, comprising a frame element having a circular mounting flange and an external thread and an internal thread, a piercing element having an external thread and a screw cap with an internal thread wherein the piercing element in the injection-moulding position is produced on the end of the frame element opposed to the mounting flange and injection-moulded integrally therewith via connecting bridges and wherein the piercing element in the assembly position of the pouring element is arranged inside the frame element.

The invention relates to a reclosable pouring element for cardboard/plastic composite packagings, in particular beverage packagings, consisting of a frame element having a circular mounting flange and an external thread, a piercing element having an external thread and an internal thread and a screw cap with an internal thread, wherein the piercing element in the injection-moulding position is produced on the end of the frame element opposed to the mounting flange and injection-moulded integrally therewith via connecting bridges and wherein the piercing element in the assembly position of the pouring element is arranged inside the frame element.

Reclosable pouring elements for one-way packagings have been known in various designs for a long time. In this case designs with a screw cap are particularly popular, since they ensure reliably tight reclosing, so that these can be shaken after packaging has been reclosed, without any of the content being able to escape.

Such pouring elements are frequently constructed in three pieces, wherein a frame element provided with a circular flange is firmly connected to the upper side of the composite packaging. Due to the interaction with the screw cap, the actual shape of the frame is cylindrical, wherein there is arranged inside the cylinder a piercing element, which, operated by the screw cap, has the function of opening the composite packaging, by it being moved, when the screw cap is opened for the first time, out of the frame element into the inside of the composite packaging, so that a pouring opening is created below the pouring element.

The pouring element specified at the beginning and described in detail above is known from WO 02/28728 A1. Due to the firm connection of frame element and piercing element via connecting bridges, for assembly of this prior-art pouring element, frame element and piercing element only need to be aligned up to one another with the screw cap.

Another three-piece pouring element is described in European Patent EP 1 088 764 μl. Also here the frame element has an external thread and the screw cap has a corresponding internal thread. Also in this case the piercing element, when the screw cap is firstly operated, by corresponding threads inside the frame element or on the outer circumference of the piercing element, is forced to be pressed axially into the composite material. There, frame element and piercing element are likewise connected to one another during production by injection moulding, however, the piercing element at the flange end of the frame element is connected thereto. During assembly therefore piercing element and screw cap must be guided on or into the frame element from different sides with opposing movements.

In addition WO 2004/000667 discloses a three-piece pouring element, wherein however the opening element is not moved by screwing. The actual opening operation is carried out here rather by a combination of a puncturing and a rotating movement, that is to say a combination of an axial and a radial movement.

Also a pouring element is already known from U.S. Pat. No. 5,141,133, wherein screw cap and piercing element are produced integrally. This pouring element is attached from the outside with its flange on the composite packaging. In this case the cylindrical frame has an internal thread in its upper region, wherein the screw cap is provided with a corresponding external thread. When the screw cap is opened the piercing element arranged in axial guides in the frame element is pressed downwards through the packaging material, as a result of which the packaging is opened.

On this basis the object of the present invention is to configure and refine the pouring element for cardboard/plastic composite packagings mentioned at the beginning and described in detail further above, in such a way that, still maintaining simple three-piece construction, particularly simple assembly and good cohesion of the pre-mounted pouring element are achieved. In addition reliable puncturing of the foil spanning the pouring opening should be ensured when it is firstly opened.

The object is achieved in that the external thread of the piercing element consists of two thread sections, which in each case extend approximately over a quarter of the circumference of the piercing element and have a pitch, which is steeper than the internal thread of the screw cap and in that the piercing element has cams, radially protruding and arranged distributed on the circumference of its outer side, which axially extend from the upper edge of the piercing element to beyond the external thread, in such a manner that they form a shoulder for the piercing element pressed inside the frame element during assembly.

The invention recognized that the piercing element in this way is always in a defined position: After removal from the injection mould, several radial connecting bridges arranged distributed on the circumference, which run between the lower surface of the piercing element and the upper edge of the frame element and which are only destroyed when telescoped, are provided for the connection between frame element and piercing element. Subsequently the piercing element is reliably prevented from falling out from the downwardly open frame element during transport or application to the composite packaging. Also in the case of a pouring element already applied to the composite packaging, the PE layer of the over-coated pouring opening lying underneath cannot be damaged, since the piercing element having the actual piercing organs is arranged so as to be protected inside the frame element.

In addition simultaneous axial telescoping of the screw cap placed on the unit consisting of piercing element and frame element is sufficient to permit final assembly of the pouring element to be applied to a composite packaging.

According to another teaching of the invention the frame element has at least one internal thread, which consists of two thread sections, which in each case extend approximately over a quarter of the circumference and have a pitch, which corresponds to the pitch of the external thread of the piercing element. Such a steep thread pitch means that when the screw cap is twisted off, the piercing element is moved very quickly with a piercing rotary motion (combined turning and axial movement) into the over-coated pouring opening, so that the foil is reliably destroyed and pressed inside the packaging, without being torn off completely since the piercing element does not make a full turn.

A further preferred embodiment of the invention makes provision for the external thread of the frame element to be double-threaded and interact with the internal thread in the screw cap. For easier (axial) application of the screw cap it is advantageous if the external thread in a preferred arrangement of the invention consists of a plurality of individual thread sections at a distance from each other with short interruptions.

In accordance with a further arrangement of the invention the frame element on its lower internal circumference has a circular and downward-pointing lip. This is advantageous from a production point of view when the injection-moulded frame element/piercing element assembly is released from the mould and in addition the lip serves as a shoulder for the piercing element twisted into the frame element during opening.

A further teaching of the invention makes provision for the piercing element to have a plurality of projections, arranged on the circumference and aligned radially outwards, which interact with corresponding internal cams of the frame element, in order to prevent the piercing element unscrewing from the frame element. They release the rotation of the piercing element when the screw cap is twisted just in one direction, by only allowing anti-clockwise turning. These projections can be formed either by the cams protruding radially on the outer side of the piercing element and/or by in each case horizontal extensions of the upper ends of the thread sections. More preferably the cams and the thread sections merge into one another.

According to another further embodiment of the invention provision is made for the piercing element on its outer side to have a plurality of radially protruding cams arranged distributed on the circumference, which extend downwards from the upper edge of the piercing element and in their form correspond to the cams of the piercing element already described. Preferably the lower ends of all cams lie in a common plane, extending perpendicularly to the vertical axis of the piercing element and thus serve for safe support on the lip at the internal end of the frame element.

In accordance with a further preferred embodiment of the invention the screw cap has at least one inner-lying force transfer means, which when the screw cap is untwisted for the first time causes the piercing element to move via protruding cams arranged inside the piercing element. Such force transfer means is preferably implemented trapezoidally and concentrically curved towards the screw cap and during the assembly operation facilitates the alignment of the screw cap relative to the piercing element.

A pouring element produced according to the method according to the invention preferably has an tamper-proof seal. This can be formed by a flat element injection-moulded integrally with the screw cap and radially projecting therefrom, which is firmly connected to the flange of the frame element, wherein the element is connected to the screw cap with at least one destroyable material bridge.

Furthermore the alignment relative to the frame element is facilitated during the assembly operation of the screw cap provided with such an tamper-proof seal. However other versions of originality closures are known per se, such as for example a band surrounding the screw cap or the like (designated in WO 2004/000667 A1 as ‘guarantee band 25’).

The invention is described below in detail on the basis of a drawing illustrating only one preferred exemplary embodiment, wherein:

FIG. 1 shows a reclosable pouring element according to the invention before assembly in vertical section,

FIG. 2 shows a frame element and a piercing element injection-moulded integrally therewith before final assembly in perspective view,

FIG. 3 shows the pouring element according to the invention in accordance with FIG. 2 during assembly in vertical section, wherein the screw cap already overlaps the piercing element,

FIG. 4 shows the finally assembled and axially telescoped pouring element in vertical section,

FIG. 5 shows the finally assembled and axially telescoped pouring element in perspective view,

FIG. 6 shows the piercing element pushed into the frame element before the opening operation, cut out in perspective plan view,

FIG. 7 shows the piercing element pushed into the frame element during the opening operation, cut out in perspective illustration,

FIG. 8 shows the piercing element pushed into the frame element after the opening operation, cut out in perspective illustration and

FIG. 9 shows the piercing element, pushed into the frame element, cut along line IX-IX from FIG. 8 in perspective illustration.

A preferred embodiment of a pouring element according to the invention is illustrated in the figures, in order to clarify the process steps in its production and its functional mode during opening. In this case in FIG. 1 a pouring element according to the invention is illustrated in longitudinal section, consisting of a frame element 1, piercing element 2 injection-moulded integrally with the frame element 1 thereover and a screw cap 3. The frame element 1 in its cylindrical main body has an external thread 4 and a circular flange 5 for attaching to a (not illustrated) composite packaging. Inside the frame element 1 a thread section 6A can be seen. To assist in understanding, the sub-assembly consisting of frame element 1 and piercing element is illustrated perspectively in FIG. 2. There, a thread section 7A, corresponding to the thread section 6A, of an external thread 7 of the piercing element 2 can be recognized, wherein both thread sections 6A and 7A have the same very steep pitch, compared to the external thread 4.

From FIG. 1 it is again evident that the frame element 1 at its lower internal end has a circular lip 8, whose function is described in detail below.

Moreover a cam 9 protruding inwards, serving as a shoulder for the piercing element 2, which will be discussed in greater detail lower down, can be recognized on the upper edge of the frame element 1.

From FIG. 2 it is evident that the piercing element, on its upper circumference, has a plurality of cams, which protrude radially outwards, wherein two opposite-lying cams 10 are arranged above the thread sections 7A and 7B in each case. Further cams 11 and 12, of which only the front of the opposite lying pairs are to be recognized in each case, are integrally connected to a horizontal extension 7D of the thread section 72 in the illustrated and to this extent preferred exemplary embodiment. On the opposite lying side a horizontal extension 7C of the thread section 7A can also be recognized. However it is also possible to dispense with the cams 12 and the extension 7C and 7D.

In the cut out according to FIG. 1 circularly arranged teeth 13 of the piercing element 2 are also to be clearly recognized. These teeth 13 have sharply formed flanks in the preferred and illustrated exemplary embodiment. In the upper internal area of the piercing element 2 radially inwardly protruding cams 14 are again to be recognized, as evident particularly clearly from FIG. 2. The frame element 1 is connected to the piercing element 2 by connecting bridges 15, as is also evident from FIG. 2.

The screw cap 3 has an internal thread 16 corresponding to the pitch of the external thread 4 of the frame element 1 and inner-lying force transfer means 17 running substantially trapezoidally and concentrically towards the screw cap. The force transfer means 17, when the pouring element is firstly opened, causes the piercing element to turn along the thread sections 6 and 7 with the aid of the cams 14 protruding inwards and thus to axially penetrate inside the packaging.

For assembling the pouring element according to the invention the screw cap 3 is now next moved over the piercing element 2 projecting from the frame element 1, as illustrated in FIG. 3. The remaining reference symbols in FIG. 3 correspond to those of FIGS. 1 and 2.

FIG. 4 now shows the finally assembled pouring element in vertical section, wherein as a result of the axial movement of the applied screw cap 3 the piercing element 2 is also axially moved inside the frame element 1, without moving rotationally. It is clearly recognized that the tips of the teeth 13 are also arranged at a distance from the lower edge of the frame element 1.

Due to the special formation of the force transfer means 17 exact positioning and alignment of both constructional elements are not necessary. As a result of further axial pressing together the connecting bridges 15 rupture and the piercing element 2 is pushed into the frame element 1, wherein the screw cap 3 is bounced onto the frame element 1 at the same time, so that the external thread 4 of the frame element 1 comes into contact with the internal thread 16 of the screw cap 3.

In FIG. 5 the finally assembled pouring element is again shown perspectively for better clarity. Here, it can be seen that the pouring element according to the invention also has an tamper-proof seal: for this purpose a plate 18 is injection moulded integrally onto the screw cap 3, which communicates via connecting bridges 19 with the screw cap 3, as is clearly evident from FIG. 5. In the present case the plate 18 on its underside has two spigots 20, which engage in corresponding recesses 22 (FIG. 2) of the flange 5 of the frame element 1, which are caulked from below for rigid connection.

FIGS. 6 to 9 finally describe the function of the pouring element according to the invention during the first opening operation of the screw cap 3. Next, the assembly position from FIGS. 4 and 5, however without screw cap 3, is shown in FIG. 6. Here it is recognizable that the inner-lying cams 9 interact with the outer-lying cams 11 or the end of the extensions 7C and 7D of the thread sections 7A or 7B connected integrally to the cams 11. This interlocking means that unscrewing of the piercing element 2 upwards from the frame element 1 is reliably rendered impossible, since the piercing element 2 can only be turned anti-clockwise when the screw cap 3 is twisted off.

FIG. 7 now shows a state, wherein the teeth are in direct contact with the foil (not illustrated) to be punctured. It is clearly evident that the lower edges of the cams 10 reach down to the respective thread section 6A or 6B of the internal thread of the frame element 1. Despite the in each case only one-piece thread sections 6A, 6B or 7A, 7B reliable guidance for the necessary rotary piercing movement is achieved.

FIGS. 8 and 9 show the piercing element 2 in its final position, where it also remains after further use of the screw cap 3 by repeated twisting on or off and in this way reliably holds back the opened foil from the pouring channel. Here it is recognizable that both the cams 10 (FIG. 8) and the cams 11 (FIG. 9) with their lower edge line up on the lip 8 and in this way fix the piercing element 2. The same applies to the cams 12 which are not recognizable here. Furthermore cams 10, 11 and 12 all arranged lying in each case diametrically opposed to one another reliably ensure that the piercing element 2 cannot fall inside the packaging. 

1-15. (canceled)
 16. A reclosable pouring element for cardboard/plastic composite packagings, in particular beverage packagings, comprising: a frame element having a circular mounting flange and an external thread and an internal thread; a piercing element having an external thread and a screw cap with an internal thread; wherein the piercing element in an injection-moulding position is produced on an end of the frame element opposed to the mounting flange and injection-moulded integrally therewith via connecting bridges and wherein the piercing element in an assembly position of the pouring element is arranged inside the frame element, wherein the external thread comprises two thread sections with each thread section extending at least a quarter of the circumference of the piercing element and having a pitch which is steeper than the internal thread of the screw cap, wherein the internal thread comprises two thread sections, with each thread section extending at least a quarter of the circumference and having a pitch which corresponds to the pitch of the external thread of the piercing element and wherein the piercing element has at least one first cam radially protruding and distributed on the circumference of an outer side of the piercing element, each cam extends from the upper edge of the piercing element to beyond the external thread in such a manner that the lower edge of each cam with the respective thread sections of the internal thread form a shoulder for the piercing element to be pressed inside the frame element during assembly.
 17. The pouring element according to claim 16, wherein the external thread of the frame element is double-threaded and interacts with the internal thread in the screw cap.
 18. The pouring element according to claim 16, wherein the external thread consists of a plurality of individual thread sections.
 19. The pouring element according to claim 16, wherein the frame element has a circular and downward pointing lip on its lower internal circumference.
 20. The pouring element according to claim 16, wherein the piercing element has a plurality of projections arranged on the circumference and aligned radially outwards, the projections interact with corresponding internal cams of the frame element, in order to prevent the piercing element from unscrewing from the frame element.
 21. The pouring element according to claim 20, wherein the projections are formed by at least one second cam protruding radially on the outer side of the piercing element.
 22. The pouring element according to claim 20, wherein the projections are formed by horizontal extensions of the upper ends of the thread sections.
 23. The pouring element according to claim 21, wherein each second cam and the thread sections of the external thread of the cutting element merge into one another.
 24. The pouring element according to claim 16, wherein the piercing element on its outer side has a plurality of radially protruding cams distributed on the circumference, each cam extending downwards from the upper edge of the piercing element.
 25. The pouring element according to claim 21, wherein the lower ends of each first cam and each second cam lie in a common plane, extending perpendicularly to a vertical axis of the piercing element in order to be supported on the lip when the piercing element is protruding from the frame element.
 26. The pouring element according to claim 24, wherein the lower ends of the plurality of radially protruding cams lie in a common plane extending perpendicularly to a vertical axis of the piercing element in order to be supported on the lip when the piercing element is protruding from the frame element.
 27. The pouring element according to claim 16, wherein the screw cap has at least one inner-lying force transfer element, which when the screw cap is untwisted for the first time causes the piercing element to move via cams arranged inside the piercing element.
 28. The pouring element according to claim 16, wherein each force transfer element is substantially trapezoidally shaped and orientated concentrically towards the screw cap.
 29. The pouring element according to claim 16, wherein the pouring element has a tamper-proof seal.
 30. The pouring element according to claim 24, wherein a flat plate firmly connected to the flange of the frame element before final assembly of the pouring element and injection-moulded integrally with the screw cap and radially projecting therefrom, serves as a tamper-proof seal. 